BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

GMAT PREP 2

Expert replies
Source: — Problem Solving |

by rishi235 » Mon Aug 18, 2008 9:17 pm
Hi heres my solution:
According to the conditions given, we get the following equations:

70% of 800 - Y shud b equal to 60% of the total employees of the company

Now here v shud note that as Y employees r retiring, the total employees will also b reduced by Y

Hence we get the following equation:

70% of 800 - Y = 60% of (800-Y)
Solving v get Y = 80 / 0.4
Hence Y = 200....Hence Ans = A

Ur mistake was that u didn't negate Y from the RHS of the equation, in which case we get the ans as 80 (Which is wrong because of the reasons mentioned above)

Hope this helps!!!
Join the discussion

by warlock » Mon Aug 18, 2008 11:09 pm
thank you rishi235..
finally got the logic..
Join the discussion

by dbart06 » Tue Aug 19, 2008 12:12 pm
Not following how you got y=80/.4
Is the equation: (800-y).7=(800-y).6 or am I missing something
Join the discussion

by Suyog » Tue Aug 19, 2008 6:53 pm
@dbart06

we have to take 70% of 800 then - y on LHS
and 60% (800-y) on RHS

I hope you will figure out now..right?
Join the discussion

by dbart06 » Wed Aug 20, 2008 7:31 am
Still confused by method.

800(.7) - y = (800-y).6 => 560-y=480-.6y How is y = 200?

Sub 480 from 560 = 80, add y to rhs =-.5y = 80/.5 = 160
Join the discussion

by sudhir3127 » Wed Aug 20, 2008 9:04 am
dbart06 wrote:Still confused by method.

800(.7) - y = (800-y).6 => 560-y=480-.6y How is y = 200?

Sub 480 from 560 = 80, add y to rhs =-.5y = 80/.5 = 160
uptill this step ur right " 560-y=480-.6y "

take the 480 on the left hand side and Y on the right hand side

560-480 = -0.6y+Y
80 = Y( -0.6+1)

80 = 0.4Y

Y = 80/0.4 = 200

Hope its clear now..
Join the discussion